‘We know about you’: Indiana police issue warning to killer of Delphi teenagers Libby German and Abby Williams

Authorities in Indiana believe they could be closing in on identifying whoever is responsible for the deaths of teenagers Abby Williams and Libby German nearly five years ago.

“My resolve to catch him is as strong as it was Day 1,” Indiana State Police Superintendent Doug Carter told Good Morning America, warning the culprit: “But the difference now between now and Day 1 is we know about you, a lot about you. Today could be the day. Sleep well.”

On February 13, 2017, Williams, 13, and 14-year-old German went for a hike on the Monon High Bridge Trail in Delphi around 1 p.m. The pair went missing and their bodies were found the following day.

Before her murder, German managed to record a short iPhone video of her and Williams' suspected killer as well as audio of his voice as he told the two: “Guys…down the hill.”

Police have also uncovered a fake social media profile using the handle “anthony_shots” that could be connected to the case. Whoever created the account attempted to solicit nude images, obtain addresses and meet juvenile females, according to investigators.

In December, officials requested anyone who had any interaction at all with the person behind the account to come forward to investigators.

“That’s generated a tremendous number of leads for us, and that’s as far as I can go,” Carter told GMA.

Today, double-homicide victims Williams and German would have been 18 and 19.

“She would have turned into a really good young lady,” German’s mother Anna said, noting her daughter maybe would have been ‘finishing up her freshman year in college.”

Anna German believes the case can be cracked with the right piece of information.

“It’s probably the smallest thing, but it’s that small thing that we’re missing and that’s what we just keep hoping for is that that one small thing will come to light and that this will be over soon,” she said.

The FBI has released a sketch of the suspect, describing him as a white male between 5'6" and 5'10", weighing 180 to 220 pounds, with reddish-brown hair. Authorities believe he is between 18 and 40 years old.

Anyone with information is requested to call the Tip Line at (765) 822-3535 or submit tips online at abbyandlibbytip@cacoshrf.com.